Justicia obliqua J.R.I.Wood & P.Gallego, 2023

P. C., Gallego, Wood, J. R. I. & American, South, 2023, Anisophylly in South American Acanthaceae, Rheedea 33 (4), pp. 221-245 : 231-232

Justicia obliqua J.R.I.Wood & P.Gallego , sp. nov. Fig. 5

Strongly anisophyllous subshrub with woody stems, subsessile, strongly oblique leaves superficially somewhat similar to Justicia imparifolia described below but the leaves hirsute (not nearly glabrous), bracts<8mm long (not 11–18 mm) and calyx4-lobed, densely pilose (not 5-lobed, thinly pubescent).

Type: PERU, Ucayali, Coronel Portillo, Padre Abad, La Divisoria , cerca Río Chino , 1400–1600 m, 11.06.1976, J. Schunke V. 9215 (holo MO [ MO2736883 !]; iso F!, US [ US 2901548!], USM [ USM88453 !]) .

Perennial anisophyllous herbs or subshrubs 0.5–1 m high. Stems at first rooting at the nodes, forming low ground cover, then ascending or erect to 1 m, usually conspicuously zigzag, pilose with multicellular hairs on younger stems, scurfy-pubescent on older growth. Leaves very unequal, subsessile to shortly petiolate, softly pilose with multicellular hairs; larger leaves 1.6– 3.5 × 0.6–1.5 cm, asymmetrically oblong-lanceolate to narrowly oblong-elliptic, apex obtuse, base cuneate, oblique; smaller leaves obliquely suborbicular, 0.3–0.9 cm in diam. Petioles 0–2 mm, pilose. Inflorescence of shortly pedunculate, terminal spikes 1–2 cm long (sometimes also from the uppermost leaf axils); peduncles 0.5 cm, pilose. Bracts and bracteoles similar, 7–7.5(–8) × 0.5–0.75 mm, linear-filiform, pilose. Calyx 4-lobed; lobes linear-lanceolate, c. 9 × 0.5 mm, pilose, pale green with a distinct midrib. Corolla magenta with pale tube, glandular-pubescent, 2.3–2.7 cm, long, 2-lipped, tube 12–18 mm long, gradually widened from c. 2 mm at base to 4.5 mm at mouth, upper lip 6–7 mm long, erect, entire, slightly hooded, lower lip recurved, 8–11 mm long, 3-lobed, lobes broadly oblong, c. 3 × 2 mm. Stamens included in upper lip, filaments c. 8 mm long, white, anthers bithecous; thecae 1.25 × 0.75 mm, ellipsoid, basally acute, white, obscurely asperous, weakly superposed. Ovary narrowly ovoid, comose; style thinly pubescent below, glabrous upwards, stigma white. Capsule and seeds not seen.

Flowering & fruiting: Found in flower from February to September.

Habitat: ‘Bosque alto tropical en sombra’ – in shade in primary tropical forest, on humid soil, on margins and clearings in dense cloud forest, 700–1800 m.

Distribution: Endemic to Peru. Moist hill forest around La Divisoria, where the departments of Huánuco and Ucayali meet ( Fig. 4 ).

Etymology: The name obliqua refers to the distinct oblique, unequal leaf base characteristic of this species.

Specimens examined: PERU, Huánuco, Coronel Portillo , Divisoria, Tingo María–Pucallpa, 1600– 1800 m, 28.02.1947, R. Ferreyra 1676 (US, USM) ; Cordillera Azul east of Tingo María, east of Koenig’s, 22.06.1959, M.E. Mathias & D. Taylor 3465 (F, MO) ; Coronel Portillo , Padre Abad, La Divisoria, carretera a Pucallpa, 1400–1600 m, 26.04.1980, J. Schunke V. 11408 ( MO, US, USM) ; La Divisoria, Tingo María– Aguaytia , Cordillera Azul, 1500–1600 m, 03.06.1983, A. Gentry et al. 41439 ( MO, US, USM) ; Leoncio Prado , Dist. Pucayacu, sector Nueva Esperanza, P.N. Cordillera Azul, S 8°29’29”, W 76°05’42.7”, 1362 m, 21.06.2017, L. Valenzuela et al. 32048 ( USM) . Ucayali, Divisoria , 700 m, 02.08.1942, V. Cárdenas USM no. 13843 ( US, USM) ; La Divisoria, Plantación Margarita , 14.08.1946, R. Ferreyra 988 ( US) ; Leoncio Prado , 80 km NE of Tingo María towards Aguaytia, near Divisoria, 1600 m, 13.09.1946, F. Woytkowski 34522 (F, MO) ; Ibid. , 900 m, 18.01.1976, A. Gentry et al. 16034 ( MO) ; Leoncio Prado , Divisoria, 1610 m, 31.05.1978, L.E. Skog et al. 5118 ( US) ; W of the limit with Ucayali , S 9°05’, W 75°46’, 10.08.1980, A. Gentry et al. 29600 (F, MO, USM) .

Conservation status: Justicia obliqua has an Area of Occupancy ( AOO) of 36 km ² and an Extent of Occurrence ( EOO) spanning 1000 km ², based on 12 collections, geographically separated in three different sub-populations. Most records come from foothill and mountain ecosystems along the Federico Basadre Highway, between the Huánuco and Ucayali departments. According to Bax et al. (2016), this paved road, constructed in the 1940s, has served as the primary catalyst for deforestation in the Ucayali region. Its existence has led to a landscape deeply fragmented by various human activities, including shifting cultivation, commercial agriculture, timber extraction, and cattle ranching, among other alterations to land use ( Ichikawa et al., 2014). However, one population has been found within the limits of the Cordillera Azul National Park and it is plausible that distribution of this species covers a wide area extending into regions integrated within the national system of protected areas. In consequence, we propose that it should be considered as Endangrered[EN] according to criteria B1a+B2ab(i,ii,iv).

Figures

Fig. 5. Justicia obliqua J.R.I.Wood & P.Gallego: a. Habit; b. Leaf; c. Detail of abaxial surface of leaf; d. Bract; e. Bracteole; f. Calyx; g. Corolla opened out to show androecium; h. Anthers; j. Ovary (from Schunke 9215; drawn by Margaret Tebbs).

Fig. 4. Distributionof selected anisophyllous species ofJusticia L.inPeru:J.impar J.R.I.Wood& P.Gallego(greensquares);J.imparifolia J.R.I.Wood & P.Gallego (red circles); J. microcalyx J.R.I.Wood & P.Gallego (pale brown triangle); J. obliqua J.R.I.Wood & P.Gallego (violet diamonds). Map prepared using QGIS v.3.28.2 (QGIS Development Team, 2023).